EtSH is the strongest acid, so EtS- is the weakest conjugate base. Two trends operate - electronegativity increases as you move to the right in the periodic table (thus O and S are more electronegative than N and P). Thus these atoms are better able to stabilize (-) charge. The other trend is that atomic size increases moving down in the table, so S is biggest than O. The larger an atom is, the more it is able to \"spread out\" the negative charge, stabilizing it (in other words, a charge of (-) is much smaller in relation to the total number of charges present, and the electron cloud can better accomodate the imbalance). Solution EtSH is the strongest acid, so EtS- is the weakest conjugate base. Two trends operate - electronegativity increases as you move to the right in the periodic table (thus O and S are more electronegative than N and P). Thus these atoms are better able to stabilize (-) charge. The other trend is that atomic size increases moving down in the table, so S is biggest than O. The larger an atom is, the more it is able to \"spread out\" the negative charge, stabilizing it (in other words, a charge of (-) is much smaller in relation to the total number of charges present, and the electron cloud can better accomodate the imbalance)..

1. EtSH is the strongest acid, so EtS- is the weakest conjugate base. Two trends operate -
electronegativity increases as you move to the right in the periodic table (thus O and S are more
electronegative than N and P). Thus these atoms are better able to stabilize (-) charge. The other
trend is that atomic size increases moving down in the table, so S is biggest than O. The larger an
atom is, the more it is able to "spread out" the negative charge, stabilizing it (in other words, a
charge of (-) is much smaller in relation to the total number of charges present, and the electron
cloud can better accomodate the imbalance).
Solution
EtSH is the strongest acid, so EtS- is the weakest conjugate base. Two trends operate -
electronegativity increases as you move to the right in the periodic table (thus O and S are more
electronegative than N and P). Thus these atoms are better able to stabilize (-) charge. The other
trend is that atomic size increases moving down in the table, so S is biggest than O. The larger an
atom is, the more it is able to "spread out" the negative charge, stabilizing it (in other words, a
charge of (-) is much smaller in relation to the total number of charges present, and the electron
cloud can better accomodate the imbalance).